1. Field of the Invention
The present invention relates to a method for producing a non-aqueous vinyl resin using a silicone oil as a polymerization solvent, and more particularly to a method for producing a vinyl resin which is effective as a treatment for fiber, paper, and the surfaces of plastic and metal; printing ink; toner for electrophotography; coating compounds; and a material for a rubber roller and a coating resin thereof.
2. Discussion of Background
Various methods for producing vinyl resins are conventionally known, as disclosed in Japanese Patent Publications 40-19186, 45-14545 and 56-9189. In these conventional methods aromatic hydrocarbons such as toluene, xylene and benzene; esters; alcohols; and aliphatic hydrocarbons such as n-hexane, n-heptane, isooctane and isododecane and mixtures thereof are used as a solvent for polymerization.
The above-mentioned polymerization solvents have the advantages that they are cheap in cost, the solubility of resins therein are high and the volatility thereof is high.
However, they are disadvantageous from the hygienic viewpoint because they have odors and toxicity. Moreover, they have the problem of safety due to their low flash ignition temperature. In addition, since these solvents have a low boiling point, the polymerization temperature is limited. In particular, when the polymerization is carried out under application of heat using the aliphatic hydrocarbon-type solvent, the odor generated from the solvent becomes more and more strong as the solvent is oxidized in the polymerization reaction.
Furthermore, the conventional polymerization solvents are scarcely expected to increase the rate of polymerization of monomers, and to improve the characteristics of the obtained resin, such as water- and oil-repellency and the electrical insulating properties.
In addition to the above, when the aforementioned solvents are employed for preparation of the resin, a troublesome process is required to separate the obtained resin from the solvent at the final stage, for instance, by drying under application of heat, drying in a vacuum, or causing the resin to precipitate in a bad solvent. This is because the solubility of the resin in the aforementioned solvents is high.